Improvement in center-wheels for watches



M. (3. SMITH.

Center-Wheel for Watches. 7

N0.59,363. PatentedFeb.2,l875.

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UNITED STATES PATENT OFFICE.

MARTIN 0. SMITH, OF EARLVILLE, ILLINOIS.

IMPROVEMENT IN CENTER-WHEELS FOR WATCHES.

Specification forming part of Letters Patent N0.159,363, dated Fol ruary 2, 1875; application filed December 27, 1873.

To all whom it may concern:

Be it known that I, MARTIN 0. SMITH, of Earlville, in the county of La Salle and State of Illinois, have invented a new and valuable Improrement in W atch-Wheels; and I do here by declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the annexed drawings making a part of this specification, and to the letters and figures of reference marked thereon.

Figure 1 of the drawings is a representation of a side view of my device. Fig. 2 is a sectional view of the same. Fig. 3 is a side, and Figs. 4 and 5 detail views of the same.

This invention has relation to self releasing and tightening devices which are applicable to the center-wheel pinions of the American watches.

The nature of my lnvention consists in a collar which has serrations on one end and doubleinclined planes on its other end, in combination with a center-wheel pinion having serrations formed on one end, and also with feathers formed on the setting-post, as will be hereinafter explained.

The following is a description of my invention:

In the annexed drawings A represents a center-wheel, which is keyed on its settingpost C; and B designates a center-wheel pinion, which is applied 011 the enlarged cylindrical portion cot the post 0, and constructed with an annular series of V-shaped radial serrations, a, on one end. D designates a collar, which is applied on the reduced portion 6 of post 0, between two feat-hers, c c, and the pinion B. This collarhas V-shaped radial serrations a on one end, which correspond to, and engage with, the serrations a on center-pinion 13. ()n the other end of collar D two inclined planes, b b, are formed, each one of which is semicircular, as shown by Figs. 4 and 5. The feathers c c are formed on the post 0 diametrically opposite each other, and have their ends beveled to correspond to the inclined planes la b of collar D, and for the purpose of allowing this collar to be applied on its post I form grooves t i in it, as shown in Figs. 2 and 5.

When the collar D is applied on the post (I and turned in a direction corresponding to the direction given to it by the inainspring of a watch, when such spring is wound up the beveled or inclined surfaces 1) b will bear against the feathers c c and force the pinion D snugly against the center-wheel A, thus en gaging teeth a a and locking the center-pinion fast to its post 0. In the event of the mainspring being broken the recoil of this spring will turn back the collar D, and thus loosen the pinion B and allow it to turn freely. I thus prevent the teeth of the train of wheels from being broken when a mainspriug breaks.

\Vhat I claim as new, and desire to secure by Letters Patent, is-

1. The collar D, having serrations a on its upper end, and double inclined planes b b on the lower end, in combination with the centerpinion 13, provided with radial serrations a, and the feathers c c of post 0, substantially as shown and described.

2. The post 0, having diametrically opposite each other the feathers c, and their upper ends beveled to correspond to the inclined planes 1), as specified.

In testimony that I claim the above I have hereunto subscribed my name in the presence of two witnesses.

MARTIN O. SMITH.

Attest WM. R. HAIGHT, WILLIAM WIESON. 

